Providing a seal around electrical wires that communicate electrical power to submerged electric devices is a problem in many applications. This is particularly a problem when the electrical wires extend through the wall of a container or housing containing pressurized water.
One example of a device in which this problem can occur is a water treatment apparatus utilizing membrane separation technology. In this type of device high pressure submerged pumps are used to pressurize and circulate water to membrane separators at pressures up to, and in some cases above, 1800 psi. The pumps are usually arranged within a housing which surrounds the pumps and contains the water which passes around and through the pumps. Electrical power is provided to the pumps through an opening in the housing by an electrical wire and therefore a seal is need to prevent high pressure water from escaping the housing.
Seals are commercially available for use in this and similar applications. These seals usually comprise a fitting for engaging a hole in the housing and an plug having one or more bores extending through it. The plug is arranged around the wire engaging the wire to provide a seal. This type of seal has been found to provide a poor seal at pressures above 100 psi and is not suitable for extended use at pressures of greater than 100 psi.
This problem also occurs with seals used with other types of electrical devices employed in applications under similar conditions, some examples of which are submerged heaters and sensing equipment.